This Is an Insta360 Mic Air Wireless Transmitter.

It is an ultra-lightweight (7.9g) microphone designed to be as small as a coin.The device features 48kHz high-quality audio capture with built-in noise reduction.It offers magnetic, clip-on, or pendant functionality for versatile wearing options.The transmitter is compatible with several Insta360 camera models, including the X5, X4, Ace Pro 2, and GO Ultra.